Should You Buy Used HVAC Equipment?

I would only suggest buying used HVAC equipment if you are an HVAC mechanic. It was a twist of fate that a rather new but defective heat pump fell into my lap.

At the start-up of my customer’s new heat pump it made a very strange noise coming from the compressor. The brand I used had a two-year complete replacement warranty if a compressor failed. And it did within a year.

My supplier sent me a brand new heat pump, and all they wanted back was the tag off the unit so it would ever be used again for any warranty. So I got to keep the heat pump with the bad compressor.

A short time later, I put a new compressor in that unit, and it’s been running perfectly since about 2010. I knew the history of the heat pump. But it was now used HVAC equipment.

I would be more inclined to buy a used air conditioner than a heat pump. Let me tell you why.

When you look at a used heat pump, it’s just a clump of steel, copper, and aluminum. You can’t tell if the maintenance was done correctly or even if the thing works. When you buy a used car, the tradition is to get in and sit down, start the engine, and go for a test drive. You may even take the car to a mechanic.

The best day in the life of a heat pump was the day it was installed. I’m referring to the second law of thermal dynamics. Things like heat pumps will eventually die and death begins the day of installation.

Even if you are thinking of picking up a free heat pump or air conditioner off Craigslist, hooking it up will run hundreds of dollars. And then, if it doesn’t work, you would have to spend another bucket of money for repairs or install a new heat pump.

Finding a good used HVAC equipment like a heat pump would be one thing, but finding the right size would be a great stroke of luck.

During the last turndown in the economy around 2008, when many people were losing their homes, it was common for them to unhook their heat pumps and air conditioners and either sell them or take them to their next location.

I replaced lots of heat pumps for people who bought those homes during that recession. I’ll bet there are a lot of stories related to those stolen bunches of used HVAC equipment

If you are considering buying a used HVAC equipment from someone who lost their home, don’t do it. It’s hot! And not in a going-to-keep-your-home warm sort of way. It’s illegal to remove anything that’s attached to your home even if you are in foreclosure.

Most of those losing their homes would grab a hacksaw and cut the copper lines, letting the refrigerant (Freon) go willy-nilly into the atmosphere—another illegal move.

Another Good Reason Not To Buy Used HVAC Equipment Like A Heat Pump

I mentioned the carelessness used when disconnecting an air conditioner or heat pump. Using a hacksaw or improper tools to disconnect a heating system that contains refrigerant introduces contaminants such as copper filings, dirt, and moisture into the system.

These contaminants will damage the unit internally—especially heat pumps. Installing a used heat pump that has been contaminated may operate successfully for a time, but its end is near.

Heat pump parts such as reversing and expansion valves are sensitive to things that end up inside the system through improper care. Reversing valves can stick and prevent the system from switching between heating and cooling.

The cost to replace a reversing valve in a heat pump can run around two grand and up. Does that make a new system taste better?

TXVs are another sensitive part of heat pumps and air conditioners. AC units don’t have reversing valves, but they do have TXVs and restriction devices that meter refrigerant flow.

An expansion device can be just a tiny orifice or a more sophisticated part that senses pressure and temperature to govern refrigerant flow through the system. The image above shows a thermal expansion valve (TXV) in the top circle.

Buying Used HVAC Equipment Off Craigslist Or eBay (Danger, Danger)

My youngest son got bitten by a fellow student in preschool. When he saw him the next day, he blurted out, “Danger, danger. That’s the attitude you should take when considering used HVAC equipment.

If you understand heat exchangers and carbon monoxide, some equipment is more acceptable to buy used, such as gas furnaces because you can see inside most of them and tell if the heat exchanger is sound or not cracked. Key words, most of them.

I saw ads on Craigslist for absolute junk. It was stuff that needed to go to the dump.

I Installed A Used Heat Pump In My Cabin

You could call it an exception to a rule. I took a gamble and acquired some used HVAC equipment. A deal like this doesn’t happen every day, but it worked beautifully.

I installed a new heat pump on a customer’s house. Upon startup, the compressor made a bad noise and began running normally. I called my supplier and asked them to make a note.

Almost one year later, the compressor failed. The supplier gave me a brand-new unit and told me to take the tag off the unit with the bad compressor. Removing the tag made it impossible for anyone to claim a future warranty, and I’m sure there are other reasons.

A few years later, I bought and installed a new compressor to heat and cool my cabin. As of 2024, it’s been running beautifully for several years.

I made an exception because I knew how it was installed and how it was removed. Clean refrigeration lines. Proper installation methods.

What Refrigerant Will Your 2nd Hand Heat Pump Use?

Years ago, the decision was made through the Montreal Protocol to discontinue the use of R-22 refrigerant.

Many used heat pumps and air conditioners out there were made to run on R-22, and with its demise, the price for R-22 skyrocketed to discontinue the manufacture of that refrigerant in mind.

New systems today run on R-410A refrigerant with Mother Earth in mind to keep her environment safe. If used equipment is what you have, you may want to check the label and verify the type of refrigerant in the unit.

Conclusion To My Experience And Thoughts

Life’s a gamble, but it’s less risky when you know some of the pitfalls. Take the time to do the dirty work and find out if things fit, and maybe a little history if you trust the information giver.

Still, in my opinion, don’t buy a used heat pump. Consider the cost of a used heat pump as a down payment toward a new system.

Another very important aspect of buying new equipment is that the efficiency of a new one is much greater than that of a used heat pump or air conditioner. Another way to pay for a new system is by having lower utility bills.